Bleaching compositions are well-known in the art. Amongst the different bleaching compositions available, those relying on bleaching by hypohalite bleaches, such as hypochlorite, are often preferred, mainly for performance reasons, especially at lower temperature.
However, there are some limitations to the convenience of hypochlorite bleaches. In particular, problems encountered with the use of hypohalite-based compositions, like hypochlorite-based compositions, are the resulting yellowing of the fabrics being bleached, which thus affects the whiteness performance. Furthermore, hypohalite based compositions are prone to be instable.
It is therefore an object of the present invention to provide a hypohalite bleach-containing composition, suitable for use in various laundry applications, which provides improved fabric whiteness to fabrics treated therewith and which has, at the same time, a commercially acceptable chemical stability along with an excellent overall stain removal performance on a wide range of stains.
The applicant has now found that the previous object can be met by formulating liquid composition comprising an alkali metal hypohalite, or mixtures thereof, and a soil suspending agent selected from the group consisting of an ethoxylated diamine, an ethoxylated polyamine, an ethoxylated amine polymer and mixture thereof, as described hereinafter.
Indeed, it has now been found that said composition allows to provide improved fabric whiteness on the fabrics treated therewith, as compared to the same composition without said soil suspending agent. Indeed, it has been found that the addition of a single compound, i.e., such a soil suspending agent, in a hypohalite bleach-containing composition, delivers improved bleaching performance and, in the same time, improved stain removal performance.
Another advantage of the compositions of the present invention is that they allow to provide outstanding fabric whitening action without compromising on the stain removal performance on different types of stains.
Moreover, the applicant has surprisingly found that the soil suspending agent, as defined herein, is chemically stable in hypochlorite-based compositions. Such a stability was unlikely to be obtained due to the chemical structure of the soil suspending agent herein. Indeed, the general thought was that such agents were prone to be decomposed and to be attacked by hypohalite bleach due to the presence of non-end protected ethoxy groups.
It has however been found that specific soil suspending agents are fully compatible with a hypohalite bleach medium, can easily be processed and have a reduced impact on the chemical stability properties of said compositions.
Indeed, the improved whitening action, and the improved stain removal performance on various stains, is maintained even for hypohalite bleaches compositions having undergone long storage periods. An advantage of the present invention is thus that chemically stable compositions are provided that are suitable to be used in the most efficient manner by the consumer over prolonged periods of time.
Another advantage of the compositions of the present invention is that said bleaching compositions are suitable for the bleaching of different types of fabrics including natural fabrics, (e.g., fabrics made of cotton, viscose, linen), synthetic fabrics such as those made of polymeric fibers of synthetic origin (e.g., polyamide-elasthane), as well as those made of both natural and synthetic fibers. Indeed, the compositions of the present invention may be used on synthetic fibers despite a standing prejudice against using hypochlorite bleaches on synthetic fibers, as evidenced by warnings on labels of commercially available hypochlorite bleaches and clothes.
Furthermore, it has been found that in a preferred embodiment of the present invention, the compositions herein may be formulated either as an emulsion or microemulsion, without the need for modifying the rheology of the compositions.
Compositions comprising soil suspending agent, as defined herein, i.e. ethoxylated diamines, ethoxylated polyamines and/or ethoxylated polymers, have been described in the art.
U.S. Pat. No. 4,659,802 discloses detergent compositions comprising ethoxylated diamines, ethoxylated polyamines and/or ethoxylated polymers as a clay soil removal antiredeposition agent. No hypohalite bleach compositions are disclosed.
EP A 111 965 discloses detergent compositions (pH=6 to 8.5) comprising ethoxylated mono- or diamines, ethoxylated polyamines and/or ethoxylated polymers as a clay soil removal/antiredeposition agent. No hypohalite bleach compositions are disclosed.
EP A 0839 903 discloses an acidic aqueous composition suitable for pretreating soiled fabrics comprising a peroxygen bleach and a soil suspending agent selected from the group consisting of an ethoxylated diamines, an ethoxylated polyamine, an ethoxylated amine polymer and mixtures thereof. No hypohalite bleach compositions are disclosed.